In order to install those blades, it is necessary to pivot their roots in the groove, such that the width of the groove is greater than the width a blade and equal to that of the blade root enlarged portions.
In addition, the filling of the groove is far from optimum since it may end up with a void equal to the clearance necessary to allow one blade root to pivot. This void then needs to be filled up with narrow wedges, but clamping is not ideal.
Furthermore, circumferential clearance exists between the caps and continuous connection does not exist.